The Standard Model Flashcards
Why invent strong nuclear?
To overcome the electrostatic repulsion of protons in nucleus
Two particles discovered following nuclear fission
- Neutron
- Neutrino
Define nucleon
A particle contained within the nucleus of an atom
Fundamental particle
A particle that is not made up of other particles
Fundamental particles in the Standard Model
- Quarks
- Leptons
Quarks
- Up
- Down
- Charm
- Strange
- Top
- Bottom
Leptons
- Electron
- Muon
- Tau
- Electron Neutrino
- Muon Neutrino
- Tau Neutrino
Bosons
Responsible for the 4 forces which interact in matter
Photon
Electroweak force
- Interaction particle
- Binds charged particles, atoms and molecules together
- Acts over long distances Includes electrostatic and magnetic forces
Gluon
Strung nuclear force
- Interaction particle
- Binds quarks together in hadrons
- Binds neutrons and protons together to form nuclei
- 10^-15m
W (+/-) boson
Quark and lepton interactions
- Interaction particle
- Interacts with other particles to change them into other particles
- Carries either a positive or negative charge and is either emitted or absorbed in quark of lepton changing interactions
- 10^-17m
Z boson
Interactions involving neutrinos
- Interaction particle
- Interacts with nuclear particles to change them into other particles
- Carries no charge and is either emitted or absorbed in weak interactions involving neutrinos
- 10^-17m
Graviton
Gravitational force
- Draws masses together
- Acts over very long distances
- Not discovered yet
Higgs Boson
An elementary particle that is produced through the quantum excitation of the Higgs field
Giving particles mass
- The Higgs field is thought to be responsible for producing mass of particles
Straight line
Leptons and quarks
Wavy lines
Photons, W and Z particles
Curly lines
Gluons
Virtual Photon
- Energy and momentum need not be related
- Continually emitted and reabsorbed
- Do not exist indefinitely
Classic representation
Charged particles interact via an electric field which transfers energy and momentum
Standard model representation
Charged particles interact by exchanging “virtual” photons, which transfer energy and momentum
Electromagnetic interactions
Exchange of virtual photons
Weak interaction
Exchange of W+, W-, Z0 bosons
Strong interaction
Exchange of virtual gluons
Gravitational interaction
Exchange of virtual gravitons (hypothetical)
Force v Interaction
Force: effect on a particle due to the presence of other particles
Interaction: Includes all forces that affect a particle, and any decays and annihilations that it may experience
Gauge boson
A form of a force carrier that can carry any of the fundamental interactions of nature that are named as forces
